/* 
 * A JavaScript implementation of the RSA Data Security, Inc. MD5 Message 
 * Digest Algorithm, as defined in RFC 1321. 
 * Copyright (C) Paul Johnston 1999 - 2000. 
 * Updated by Greg Holt 2000 - 2001. 
 * See http://pajhome.org.uk/site/legal.html for details. 
 */  
  
/* 
 * Convert a 32-bit number to a hex string with ls-byte first 
 */  
var hex_chr = "0123456789abcdef";  
function rhex(num)  
{  
  str = "";  
  for(j = 0; j <= 3; j++)  
    str += hex_chr.charAt((num >> (j * 8 + 4)) & 0x0F) +  
           hex_chr.charAt((num >> (j * 8)) & 0x0F);  
  return str;  
}  
  
/* 
 * Convert a string to a sequence of 16-word blocks, stored as an array. 
 * Append padding bits and the length, as described in the MD5 standard. 
 */  
function str2blks_MD5(str)  
{  
  nblk = ((str.length + 8) >> 6) + 1;  
  blks = new Array(nblk * 16);  
  for(i = 0; i < nblk * 16; i++) blks[i] = 0;  
  for(i = 0; i < str.length; i++)  
    blks[i >> 2] |= str.charCodeAt(i) << ((i % 4) * 8);  
  blks[i >> 2] |= 0x80 << ((i % 4) * 8);  
  blks[nblk * 16 - 2] = str.length * 8;  
  return blks;  
}  
  
/* 
 * Add integers, wrapping at 2^32. This uses 16-bit operations internally  
 * to work around bugs in some JS interpreters. 
 */  
function add(x, y)  
{  
  var lsw = (x & 0xFFFF) + (y & 0xFFFF);  
  var msw = (x >> 16) + (y >> 16) + (lsw >> 16);  
  return (msw << 16) | (lsw & 0xFFFF);  
}  
  
/* 
 * Bitwise rotate a 32-bit number to the left 
 */  
function rol(num, cnt)  
{  
  return (num << cnt) | (num >>> (32 - cnt));  
}  
  
/* 
 * These functions implement the basic operation for each round of the 
 * algorithm. 
 */  
function cmn(q, a, b, x, s, t)  
{  
  return add(rol(add(add(a, q), add(x, t)), s), b);  
}  
function ff(a, b, c, d, x, s, t)  
{  
  return cmn((b & c) | ((~b) & d), a, b, x, s, t);  
}  
function gg(a, b, c, d, x, s, t)  
{  
  return cmn((b & d) | (c & (~d)), a, b, x, s, t);  
}  
function hh(a, b, c, d, x, s, t)  
{  
  return cmn(b ^ c ^ d, a, b, x, s, t);  
}  
function ii(a, b, c, d, x, s, t)  
{  
  return cmn(c ^ (b | (~d)), a, b, x, s, t);  
}  
  
/* 
 * Take a string and return the hex representation of its MD5. 
 */  
function calcMD5(str)  
{  
  x = str2blks_MD5(str);  
  a =  1732584193;  
  b = -271733879;  
  c = -1732584194;  
  d =  271733878;  
  
  for(i = 0; i < x.length; i += 16)  
  {  
    olda = a;  
    oldb = b;  
    oldc = c;  
    oldd = d;  
  
    a = ff(a, b, c, d, x[i+ 0], 7 , -680876936);  
    d = ff(d, a, b, c, x[i+ 1], 12, -389564586);  
    c = ff(c, d, a, b, x[i+ 2], 17,  606105819);  
    b = ff(b, c, d, a, x[i+ 3], 22, -1044525330);  
    a = ff(a, b, c, d, x[i+ 4], 7 , -176418897);  
    d = ff(d, a, b, c, x[i+ 5], 12,  1200080426);  
    c = ff(c, d, a, b, x[i+ 6], 17, -1473231341);  
    b = ff(b, c, d, a, x[i+ 7], 22, -45705983);  
    a = ff(a, b, c, d, x[i+ 8], 7 ,  1770035416);  
    d = ff(d, a, b, c, x[i+ 9], 12, -1958414417);  
    c = ff(c, d, a, b, x[i+10], 17, -42063);  
    b = ff(b, c, d, a, x[i+11], 22, -1990404162);  
    a = ff(a, b, c, d, x[i+12], 7 ,  1804603682);  
    d = ff(d, a, b, c, x[i+13], 12, -40341101);  
    c = ff(c, d, a, b, x[i+14], 17, -1502002290);  
    b = ff(b, c, d, a, x[i+15], 22,  1236535329);      
  
    a = gg(a, b, c, d, x[i+ 1], 5 , -165796510);  
    d = gg(d, a, b, c, x[i+ 6], 9 , -1069501632);  
    c = gg(c, d, a, b, x[i+11], 14,  643717713);  
    b = gg(b, c, d, a, x[i+ 0], 20, -373897302);  
    a = gg(a, b, c, d, x[i+ 5], 5 , -701558691);  
    d = gg(d, a, b, c, x[i+10], 9 ,  38016083);  
    c = gg(c, d, a, b, x[i+15], 14, -660478335);  
    b = gg(b, c, d, a, x[i+ 4], 20, -405537848);  
    a = gg(a, b, c, d, x[i+ 9], 5 ,  568446438);  
    d = gg(d, a, b, c, x[i+14], 9 , -1019803690);  
    c = gg(c, d, a, b, x[i+ 3], 14, -187363961);  
    b = gg(b, c, d, a, x[i+ 8], 20,  1163531501);  
    a = gg(a, b, c, d, x[i+13], 5 , -1444681467);  
    d = gg(d, a, b, c, x[i+ 2], 9 , -51403784);  
    c = gg(c, d, a, b, x[i+ 7], 14,  1735328473);  
    b = gg(b, c, d, a, x[i+12], 20, -1926607734);  
      
    a = hh(a, b, c, d, x[i+ 5], 4 , -378558);  
    d = hh(d, a, b, c, x[i+ 8], 11, -2022574463);  
    c = hh(c, d, a, b, x[i+11], 16,  1839030562);  
    b = hh(b, c, d, a, x[i+14], 23, -35309556);  
    a = hh(a, b, c, d, x[i+ 1], 4 , -1530992060);  
    d = hh(d, a, b, c, x[i+ 4], 11,  1272893353);  
    c = hh(c, d, a, b, x[i+ 7], 16, -155497632);  
    b = hh(b, c, d, a, x[i+10], 23, -1094730640);  
    a = hh(a, b, c, d, x[i+13], 4 ,  681279174);  
    d = hh(d, a, b, c, x[i+ 0], 11, -358537222);  
    c = hh(c, d, a, b, x[i+ 3], 16, -722521979);  
    b = hh(b, c, d, a, x[i+ 6], 23,  76029189);  
    a = hh(a, b, c, d, x[i+ 9], 4 , -640364487);  
    d = hh(d, a, b, c, x[i+12], 11, -421815835);  
    c = hh(c, d, a, b, x[i+15], 16,  530742520);  
    b = hh(b, c, d, a, x[i+ 2], 23, -995338651);  
  
    a = ii(a, b, c, d, x[i+ 0], 6 , -198630844);  
    d = ii(d, a, b, c, x[i+ 7], 10,  1126891415);  
    c = ii(c, d, a, b, x[i+14], 15, -1416354905);  
    b = ii(b, c, d, a, x[i+ 5], 21, -57434055);  
    a = ii(a, b, c, d, x[i+12], 6 ,  1700485571);  
    d = ii(d, a, b, c, x[i+ 3], 10, -1894986606);  
    c = ii(c, d, a, b, x[i+10], 15, -1051523);  
    b = ii(b, c, d, a, x[i+ 1], 21, -2054922799);  
    a = ii(a, b, c, d, x[i+ 8], 6 ,  1873313359);  
    d = ii(d, a, b, c, x[i+15], 10, -30611744);  
    c = ii(c, d, a, b, x[i+ 6], 15, -1560198380);  
    b = ii(b, c, d, a, x[i+13], 21,  1309151649);  
    a = ii(a, b, c, d, x[i+ 4], 6 , -145523070);  
    d = ii(d, a, b, c, x[i+11], 10, -1120210379);  
    c = ii(c, d, a, b, x[i+ 2], 15,  718787259);  
    b = ii(b, c, d, a, x[i+ 9], 21, -343485551);  
  
    a = add(a, olda);  
    b = add(b, oldb);  
    c = add(c, oldc);  
    d = add(d, oldd);  
  }  
  return rhex(a) + rhex(b) + rhex(c) + rhex(d);  
}  